# Relationship history for MSHA mine 1102986

Current hierarchy: **VOTORANTIM CIMENTOS → VCNA Prairie LLC → Yard 99 - Ashkum**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **controller_controls_mine:** Albert E  Markgraf → Yard 99 - Ashkum; 1979-11-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Prairie Group → Yard 99 - Ashkum; 1984-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Markgraf Materials Company → Yard 99 - Ashkum; 1996-05-01 to 1997-06-11; source msha-controller-operator-history
- **controller_controls_operator:** Albert E  Markgraf → Markgraf Materials Company; 1996-05-01 to 1997-06-11; source msha-controller-operator-history
- **operator_operates_mine:** Prairie Material Sales, Inc. - Aggregate Division → Yard 99 - Ashkum; 1997-06-12 to 2008-02-01; source msha-controller-operator-history
- **controller_controls_operator:** Prairie Group → Prairie Material Sales, Inc. - Aggregate Division; 1997-06-12 to 2008-02-01; source msha-controller-operator-history
- **operator_operates_mine:** VCNA Prairie LLC → Yard 99 - Ashkum; 2008-02-02 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** VOTORANTIM CIMENTOS → Yard 99 - Ashkum; 2008-02-02 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** VOTORANTIM CIMENTOS → VCNA Prairie LLC; 2008-02-02 to current/open; source msha-controller-operator-history